yesessarily
'Yesessarily' is essentially a contraction (sans the ugly and very un-aesthetic apostrophe aka flying banana) of 'yes' and 'necessarily'. This word comes in handy far more than you would think. Used after a person says 'not necessarily!'
Person 1: All rap music sucks.
Person 2: Not necessarily!
Person 1: YESESSARILY!
Person 2: Not necessarily!
Person 1: YESESSARILY!